import { join } from 'node:path'

import dotenv from 'dotenv'
import { readFile } from 'fs-extra'

/**
 * 获取当前环境下生效的配置文件名
 */
function getConfFiles() {
  const script = process.env.npm_lifecycle_script as string
  const reg = new RegExp('--mode ([a-z_\\d]+)')
  const result = reg.exec(script)
  const mode = result?.[1]
  return [`.env.${mode}`]
}

/**
 * Get the environment variables starting with the specified prefix
 * @param match prefix
 * @param confFiles ext
 */
export async function getEnvConfig(
  match = 'VITE_GLOB_',
  confFiles = getConfFiles(),
): Promise<{
  [key: string]: string
}> {
  let envConfig = {}

  for (const confFile of confFiles) {
    try {
      const envPath = await readFile(join(process.cwd(), confFile), { encoding: 'utf8' })
      const env = dotenv.parse(envPath)
      envConfig = { ...envConfig, ...env }
    } catch (e) {
      console.error(`Error in parsing ${confFile}`, e)
    }
  }
  const reg = new RegExp(`^(${match})`)
  Object.keys(envConfig).forEach((key) => {
    if (!reg.test(key)) {
      Reflect.deleteProperty(envConfig, key)
    }
  })
  return envConfig
}
